The invention relates to gas turbine engine constructions and particularly to the design of combustor splash rings. Such splash rings function to limit the maximum temperature of the walls of the combustor. The combustors, which may be either can shaped and disposed along the sides of the engine or annular or encircle the entire engine are disposed with the exterior thereof at a higher pressure than the pressure of the compressed air reaching the inside of the combustor. The air reaching both the inside and the outside is initially compressed by the compressor section of the gas turbine engine. Combustors have typically been provided with a plurality of apertures to allow the relatively cool higher pressure air on the outside of the combustor to enter the combustor and thereby limit the maximum temperature of the wall of the combustor. It is desirable to limit the wall temperature by the use of such air to a predetermined temperature maximum which depends upon the material that is being used. It is also desirable to minimize the amount of air which passes from the outside of the combustor into the inside of the combustor through such cooling holes because the engine performance is degraded by the addition of the air passing into the combustor through the cooling holes.
Many combustor designs are relatively complex. For example, a typical combustor may utilize twelve splash rings to form the combustor liner, and one or more fuel nozzles and air swirlers. Such constructions are difficult and expensive to manufacture with present splash ring designs. In many cases it is necessary to use relatively exotic materials such as "HASTELLOY", a registered trademark of Cabot Corporation, to withstand the high wall temperatures caused by the hot gases inside the combustor.
It is an object of the invention to provide a combustor design which directs the flow of cooling air passing from the outside of the combustor to the inside of the combustor along the interior wall of the combustor to maximize the cooling effect produced by a given quantity of air.
It is another object of the invention to provide apparatus which is modular and thus permits the easy assembly of combustors of different sizes for different engine applications.
Still another object of the invention is to provide a combustor design which allows engine designs which use relatively higher combustion temperatures with known combustor wall materials.
Still another object of the invention is to provide a structure which will permit the use of materials which are widely available at reasonable costs.
Still another object of the invention is to provide apparatus which can be manufactured inexpensively utilizing relatively conventional manufacturing processes.